1. Field of the Invention
The present invention relates to an electric-component (EC) mounting method, an EC treating method, and an EC mounting apparatus, and particularly to the art of controlling the mounting or treating of electric components (ECs), in particular, electronic components.
2. Discussion of Related Art
It has been practiced to take, before an EC is mounted on a printed wiring board (PWB), an image of the EC sucked and held by a suction nozzle, as seen in a direction perpendicular to an axial direction of the nozzle parallel to an axis line thereof. Based on image data representing the thus taken image, it is judged whether the EC held by the nozzle is taking a lying-on-its-side posture, that is, whether the EC is taking an incorrect rotation position deviated by 90 degrees from a correct rotation position thereof about an axis line perpendicular to the axis line of the nozzle. If it is judged that the EC is taking the lying-on-its-side posture, the EC is not mounted on the PWB to prevent the production of a defective printed circuit board (PCB) on which the EC having the incorrect posture is mounted.
However, even the above-described method cannot prevent the production of all defective PCBs. For example, even in the case where a suction nozzle holds an EC such that the EC is not taking a lying-on-its-side posture, if the nozzle has a dimensional error with respect to its axial-direction dimension, then the distance between the EC and the PWB is adversely influenced by the dimensional error, so that the amount of access of the EC to the PWB may be excessive and accordingly the EC may be subjected to an excessive load and even be damaged, or that the amount of access of the EC to the PWB may be short and accordingly the EC may not be mounted at a correct EC-mount place on the PWB.
The above-explained problems mean that it is difficult to control appropriately the access of a suction nozzle to some member. Similar problems are experienced when a suction nozzle receives an EC from an EC supplying device. For example, if a suction nozzle has an error with respect to its axial-direction dimension and the distance between the nozzle and the EC is adversely influenced by the dimensional error, the amount of access of the nozzle to the EC may be excessive and accordingly the EC may be subjected to an excessive load and even be damaged, or the amount of access of the nozzle to the EC may be short and accordingly the nozzle may fail to suck or hold the EC.
The present invention provides an EC mounting method, an EC treating method, an EC mounting apparatus, and an EC treating apparatus which have the following features. Those features are described, like claims, in respective paragraphs which are given respective numbers. Any feature that includes another feature shall do so by referring to the number given to the latter feature. However, the following features and the appropriate combinations thereof are just examples to which the technical features, and the combinations thereof, described in the specification are by no means limited. In addition, in the case where one feature recites a plurality of items, it is not essentially required that all of those items be simultaneously employed in the one feature. That is, it is possible to select and employ only a portion (one, two, . . . , but not all) of those items.
(1) According to a first feature of the present invention, there is provided a method of mounting an electric component on a circuit substrate, the method comprising the steps of moving at least one of a suction nozzle and an electric-component supplying device toward the other of the suction nozzle and the electric-component supplying device, so that the nozzle applies a suction to the electric component supplied by the supplying device and thereby receives the component, moving at least one of the suction nozzle and the circuit substrate toward the other of the nozzle and the substrate, so that the nozzle mounts the electric component on the substrate, taking an image of at least a portion of the electric component sucked and held by the suction nozzle, as seen in a direction perpendicular to an axial direction of the nozzle, in a state in which the nozzle takes a known position in the axial direction, determining, based on image data representing the taken image, a position of at least a mounted surface of the electric component that is opposite to a sucked surface of the component sucked by the suction nozzle, and controlling, based on the determined position, a movement of at least one of the suction nozzle and at least one of the electric-component supplying device and the circuit substrate, toward the other of the nozzle and the at least one of the supplying device and the substrate.
The taking step may include taking an image of the electric component only, and the determining step may include determining a position of the mounted surface of the component only. Alternatively, the taking step may additionally include taking an image of an end portion of the suction nozzle that applies the suction, and the determining step may additionally include determining a position of a sucking end surface of the nozzle that applies the suction.
The direction of movement of at least one of the suction nozzle and at least one of the electric-component supplying device and the circuit substrate toward the other of the nozzle and the at least one of the supplying device and the substrate may be a vertical direction, or a direction inclined relative to the vertical direction.
The known position taken by the suction nozzle in the axial direction thereof is defined as that taken by a portion of the nozzle that is held by, e.g., a nozzle holder, a position of that portion relative to the nozzle holder in the axial direction being not changed by, e.g., a manufacturing error of the nozzle or wearing of the sucking end surface of the nozzle. Therefore, the position of the suction nozzle is equivalent to that of the nozzle holder. In the case where the suction nozzle is held by the nozzle holder such that the nozzle is not movable in the axial direction thereof relative to the holder, the position of the portion of the nozzle held by the holder does not change relative to the holder. Thus, if the position of the holder is known, then the position of the nozzle is also known. On the other hand, in the case where the nozzle is held by the holder such that the nozzle is movable in the axial direction relative to the holder, the position of the nozzle may not be known even if the position of the holder may be known. In the latter case, therefore, the position of the nozzle must be discussed in the state in which the nozzle takes a prescribed position relative to the holder, e.g., an advancement-end position relative to the holder.
The state in which the suction nozzle takes the known position in the axial direction may be, in the literal sense of the words, a state in which an absolute position taken by the nozzle in the axial direction is known, or may be a state in which a position taken by the nozzle in the axial direction when an image taking operation is performed is constant. In the present embodiment, it is at least needed to detect an error of the actual position of the mounted surface of the electric component from an ideal (i.e., target or correct) position, and it is not essentially needed to detect an absolute position of the mounted surface.
The known position taken by the suction nozzle may be a designed position or a measured position. The designed position means a position to be taken by the suction nozzle in a state in which an electric-component (EC) mounting system has been assembled and the fine adjustment of each element of the system has been completed. If an image taking operation is performed in a state in which the nozzle takes a prescribed position in the axial direction, the designed position can be used as the known position. On the other hand, if the nozzle does not take a prescribed position in the axial direction when an image taking operation is done, a position actually taken by the nozzle is measured, and the measured position is used as the known position. However, even if an image taking operation is performed in the state in which the nozzle takes the prescribed position in the axial direction, an actual position of the nozzle may be measured and the measured position may be used as the known position.
In the state in which the suction nozzle takes the known position, a position to be taken by the sucked surface or the mounted surface of the EC is known, if a length of the nozzle or a thickness of the EC is known. If the known position of the nozzle is a designed position, then the known position of the mounted surface or the sucked surface is also a designed position. If the known position of the nozzle is a measured position, then the known position of the mounted surface or the sucked surface is a position obtained based on the measured position.
Controlling the movement of at least one of the suction nozzle and at least one of the electric-component supplying device and the circuit substrate, toward the other of the nozzle and the at least one of the supplying device and the substrate, may include controlling at least one of (a) a limit of the movement, i.e., a minimum distance between the nozzle and the at least one of the supplying device and the substrate, (b) a position where deceleration of the movement is started, and (c) a mode of deceleration of the movement.
As described above, in the state in which the suction nozzle takes the known position, the position to be taken by the mounted surface is known, if the length of the nozzle and the thickness of the EC are known. Therefore, if an image of at least the mounted surface of the EC opposite to the sucked surface is taken, an error of the actual position of the mounted surface can be obtained. If the error of the actual position of the mounted surface is obtained, then the movement of the nozzle toward the circuit substrate can be appropriately controlled. For example, when the EC is mounted on the substrate, the EC and the substrate can be moved toward each other while the error is taken into consideration. Thus, the EC can be reliably mounted on the substrate, while the EC and the substrate are effectively prevented from being too close to each other or too distant from each other, and a failure to mount the EC or damaging the EC is effectively avoided. The error of the actual position of the mounted surface of the EC includes all errors that cause the actual position of the mounted surface to differ from the known position, such as a manufacturing error of the suction nozzle, wearing of the sucking end surface of the nozzle, or a dimensional error of the EC. If the actual position of the mounted surface is determined based on the taken image, then the EC can be mounted on the circuit substrate while an error of the actual position is taken into consideration. In the case where a dimensional error of the thickness of the EC is small, a position of the sucking end surface of the nozzle can be determined based on the position of the mounted surface of the EC and the thickness of the EC, so that the movement of the nozzle and the EC supplying device toward each other can be appropriately controlled.
If at least one of the length of the suction nozzle and the thickness of the EC changes, the position of the mounted surface of the EC changes. However, if the position of the mounted surface of the EC is obtained as an absolute position of the mounted surface relative to a reference position, then the movement of the nozzle and the circuit substrate toward each other to mount the EC on the substrate can be appropriately controlled even if there may be no data representing respective nominal dimensions of the nozzle and the EC. The absolute position of the mounted surface of the EC includes both a variation of a nominal dimension of each of the nozzle and the EC, and an error of an actual dimension of each of the nozzle and the EC from the corresponding nominal dimension. Thus, it is not needed to input, into the EC mounting system in advance, the data representing the respective nominal dimensions of the nozzle and the EC.
The position of the mounted surface of the EC changes depending upon the length of the suction nozzle. If the position of the mounted surface is obtained as an absolute position of the mounted surface relative to a reference position, the movement of the nozzle and the EC-supplying device toward each other can be appropriately controlled even if there may be no data representing the nominal dimension of the nozzle. In this case, however, it is needed to obtain a position of the sucking end surface of the nozzle, at latest before the movement of the nozzle and the EC-supplying device toward each other is started during an EC mounting operation, e.g., before the EC mounting operation itself, or before the nozzle sucks and holds an EC during the EC mounting operation.
If both the respective positions of the mounted surface of the EC and the sucking end surface of the suction nozzle are detected, the movement of the nozzle toward each of the EC-supplying device and the circuit substrate can be appropriately controlled. In addition, a thickness of the EC (i.e., the sum of a nominal dimension of the EC and an error of an actual dimension of the EC from the nominal dimension) can be obtained and, based on the thus obtained thickness, the movement of the nozzle and the EC-supplying device toward each other can be appropriately controlled.
The above explanations have been made, for easier understanding purposes, on the assumption that respective positional errors of the nozzle holder, the EC-supplying device, a circuit-substrate supporting device, and an image-taking device relative to one another in the axial direction of the suction nozzle are very small and negligible. However, in the case where those positional errors are not negligible, those errors should be taken into consideration to control the movement of the nozzle and at least one of the EC-supplying device and the circuit substrate toward each other.
(2) According to a second feature of the present invention that includes the first feature (1), the controlling step comprises controlling at least one of a position of an end of a downward movement of the suction nozzle toward the at least one of the electric-component supplying device and the circuit substrate, an end surface of the nozzle that applies the suction facing downward during the downward movement, and a position where a deceleration of the downward movement of the suction nozzle is started.
In many cases, a suction nozzle is held by a nozzle holder such that the nozzle can be advanced and retracted relative to the holder. For example, a suction nozzle is held by a nozzle holder such that the nozzle is movable relative to the holder in the axial direction of the nozzle, and is biased by a spring member, such as a compression coil spring, in a direction in which the nozzle is advanced relative to the holder, and the limit of advancement of the nozzle is defined by an advancement-limit defining device. Accordingly, after the nozzle contacts an EC supplied by the EC-supplying device or after the EC held by the nozzle contacts a circuit substrate supported by the circuit-substrate supporting device, the nozzle is retracted into the holder while elastically deforming the spring member. Thus, an excessive amount of downward movement of the nozzle holder is absorbed, and the nozzle or the EC is pressed against the EC or the substrate with an appropriate force. The spring member functions as a cushion device. In the case where the cushion device is employed, if the nozzle contacts the EC or if the EC contacts the substrate, then the nozzle is stopped and is not moved downward to a prescribed downward-movement end position, so that the nozzle or the EC is pressed against the EC or the substrate with a force which is substantially proportional to the difference between the prescribed downward-movement end position and the position where the nozzle is actually stopped. Thus, the downward-movement end position recited in the second feature (2) means the above-explained prescribed downward-movement end position, in other words, the position to which the nozzle is to be moved downward unless the nozzle is stopped. On the other hand, in the case where the cushion device is not employed, the respective amounts of downward movement of the nozzle holder and the suction nozzle are equal to each other, and accordingly the nozzle is moved downward to the prescribed downward-movement end position. In the former case where the cushion device is employed, if the nozzle sucks and holds an EC without pressing the EC, the respective amounts of downward movement of the holder and the nozzle are equal to each other. For example, if, when the holder reaches its downward-movement end position, the nozzle just contacts the EC and holds the same without elastically deforming the spring member, or if, when the holder reaches its downward-movement end position, the nozzle is positioned at a small distance from the EC and holds the same without elastically deforming the spring member, then the respective amounts of downward movement of the holder and the nozzle are equal to each other, and the nozzle sucks and holds the EC without pressing the same.
If the downward-movement end position of the suction nozzle is controlled, occurrence of a shortage or an excessiveness of downward movement of the nozzle can be avoided. Thus, the nozzle can suck and hold an EC without failure or without breaking the same, or can mount an EC on a circuit substrate without failure or without damaging the same. For example, if the position of the sucking end surface of the nozzle in the axial direction thereof is obtained in the state in which the nozzle is biased by the spring member relative to the holder toward the advancement-end position of the nozzle, the movement of the nozzle and the EC-supplying device toward each other can be appropriately or accurately controlled, based on the obtained position, so that even if the nozzle may have a nominal-dimension error, a manufacturing error, or wearing, the nozzle can suck and hold an EC while applying an appropriate pressing force to the EC, or while just contacting the EC with a pressing force substantially equal to zero, or while having a prescribed distance to the EC. Even in the case where the nozzle is not biased by the spring member relative to the holder, it is possible to accurately move the nozzle to a predetermined position such as a position where the nozzle can just contact an EC.
In the case where the position where the deceleration of the downward movement of the suction nozzle is started is controlled, the speed at which the nozzle contacts an EC or an EC held by the nozzle contacts a circuit substrate can be made sufficiently low. Thus, occurrence of damaging of EC can be avoided.
(3) According to a third feature of the present invention that includes the first or second feature (1) or (2), the method further comprising a step of holding, with a nozzle holder, the suction nozzle such that the nozzle is retractable relative to the nozzle holder, and a step of biasing, with a biasing device, the suction nozzle toward a position of an end of an advancement thereof relative to the nozzle holder.
For example, when the suction nozzle mounts an EC on a circuit substrate, the nozzle holder may be further moved toward the circuit substrate after the EC contacts the substrate. Even in this case, since the suction nozzle is retracted relative to the holder against the biasing force of the biasing device, the additional movement of the holder is allowed. Therefore, if the amount of downward movement of the holder is made somewhat excessive, the EC can reliably contact the substrate. However, since the nozzle presses the EC based on the biasing force of the biasing device, the EC may be pressed with an excessively great force, and may even be damaged, if the amount of downward movement of the holder is too much. To avoid this, the position of the mounted surface of the EC is obtained, and the movement of the nozzle and the substrate toward each other is controlled, so that the EC can be reliably contacted with the substrate and can be mounted on the same with an appropriate pressing force. This is true with the case where the suction nozzle takes an EC from the EC-supplying device. If the position of the sucking end surface of the nozzle is obtained, the movement of the nozzle and the EC-supplying device toward each other can be so controlled that the nozzle sucks and holds an EC while applying an appropriate pressing force to the same or while not applying a pressing force.
(4) According to a fourth feature of the present invention that includes any one of the first to third features (1) to (3), the determining step comprises determining, each time the suction nozzle sucks and holds one electric component, a position of at least a mounted surface of the one electric component held by the nozzle.
A position of a sucking end surface of the suction nozzle changes with, e.g., wearing of the nozzle, but this change needs a long time. Thus, it is not essentially needed to determine, for detecting the change, the position of the sucking end surface of the nozzle so frequently, e.g., each time the nozzle sucks and holds each one EC. In contrast, each one EC may have a dimensional error and/or a nominal-dimension error, and accordingly it is preferred to determine, for detecting those errors, the position of the mounted surface of each one EC each time the nozzle sucks and holds the one EC. In the latter case, the movement of the nozzle and the circuit substrate toward each other can be appropriately controlled to mount each one EC on the circuit.
(5) According to a fifth feature of the present invention that includes any one of the first to fourth features (1) to (4), the taking step comprises taking, each time a prescribed condition is satisfied, an image of an end portion of the suction nozzle that applies the suction, and the determining step comprises determining, based on the taken image, a position of an end surface of the suction nozzle that applies the suction.
For example, it is preferred to determine the position of the sucking end surface of the suction nozzle each time such a prescribed condition is satisfied that the nozzle has mounted a prescribed number of ECs after the last determination of position of the sucking end surface, that suction nozzles have been exchanged, or that a prescribed time has elapsed as recited in the following, sixth feature (6).
In the case where the prescribed condition is that the suction nozzle has mounted the prescribed number of ECs, either respective prescribed numbers or a common prescribed number may be used for a plurality of suction nozzles, respectively or commonly, which may employed. It is preferred to prescribe, for each nozzle, be such a number which corresponds to an appropriate timing when a change of the position of the sucking end surface of the each nozzle can be detected. The appropriate timing may be a timing when the detection of change of the position of the sucking end surface is too late to maintain the accuracy of mounting of ECs, or a timing when the detection is too early and accordingly is useless. The number may be prescribed based on, e.g., a transverse cross-sectional area of the sucking end surface of the each nozzle. The smaller the transverse cross-sectional area is, the easier the sucking end surface is to wear, and accordingly the smaller the prescribed number is. Alternatively, the number may be prescribed depending upon the frequency of use of the each nozzle, such that the higher the frequency of use is, the smaller the prescribed number is. In the case where a common prescribed number is used for a plurality of suction nozzles, the common number may be prescribed aiming at one of the nozzles that is most easily worn.
(6) According to a sixth feature of the present invention that includes the fifth feature (5), the prescribed condition comprises a condition that a prescribed time has elapsed.
(7) According to a seventh feature of the present invention that includes the sixth feature (6), the taking step comprises taking, when the suction nozzle first reaches an image-take position after the prescribed time has elapsed, the image of the end portion of the suction nozzle.
If the suction nozzle is mounting an EC when the prescribed time has just elapsed, the nozzle continues the current EC mounting action according to a prescribed procedure. In this case, when the nozzle reaches the image-take position, an image of the end portion of nozzle is taken.
On the other hand, if the suction nozzle is not mounting an EC when the prescribed time has just elapsed, an image of the end portion of nozzle may be taken in the state in which the nozzle is not mounting an EC, or after the nozzle has started an EC mounting action. In the former case, an operator may command, in response to an alarm indicating that the prescribed time has elapsed, the nozzle to move to the image-take position where the image of the end portion of the nozzle is taken by an image-taking device.
In either case, an image of the end portion of the suction nozzle is taken at a timing when the nozzle is not hindered from mounting an EC. That is, the image is taken without interrupting the EC mounting action of the nozzle.
(8) According to an eighth feature of the present invention that includes the sixth feature (6), the prescribed condition comprises a condition that the suction nozzle is not performing an electric-component mounting action, and the taking step comprises moving the suction nozzle to an image-take position when the prescribed time has elapsed and the suction nozzle is not performing the electric-component mounting action.
(9) According to a ninth feature of the present invention that includes any one of the sixth to eighth features (6) to (8), the taking step further comprises measuring the prescribed time only while the suction nozzle is performing each electric-component mounting action.
According to this feature, a time of lasting of each EC-mounting action is measured, and respective times measured for a plurality of EC-mounting actions are added to each other. If the sum of the thus added times reaches the prescribed time, an image is taken. Since many events, such as wearing, which cause a change of the position of the sucking end surface of the suction nozzle occur during EC-mounting actions, an image can be taken at an appropriate timing, if the prescribed time is measured only while the nozzle is performing each EC-mounting action.
(10) According to a tenth feature of the present invention, there is provided a method of mounting an electric component on a circuit substrate, the method comprising the steps of moving at least one of a suction nozzle and an electric-component supplying device toward the other of the suction nozzle and the electric-component supplying device, so that the nozzle applies a suction to the electric component supplied by the supplying device and thereby receives the component, moving at least one of the suction nozzle and the circuit substrate toward the other of the nozzle and the substrate, so that the nozzle mounts the electric component on the substrate, taking, after the suction nozzle receives the electric component and before the nozzle mounts the component, an image of the component sucked and held by the nozzle, as seen in a direction perpendicular to an axial direction of the nozzle, determining, based on image data representing the taken image, a thickness of the electric component, and controlling, based on the determined thickness, a movement of at least one of the suction nozzle and at least one of the electric-component supplying device and the circuit substrate, toward the other of the nozzle and the at least one of the supplying device and the substrate.
In the case where the position of the sucking end surface of the suction nozzle is known without taking any images, for example, where the nozzle is precisely manufactured and is precisely held by a nozzle holder and accordingly the position of the sucking end surface of the nozzle is equal to the designed position, the position of the mounted surface of each EC can be determined if the thickness of the each EC is determined. If the position of the mounted surface is determined, the movement of the nozzle and the circuit substrate toward each other can be appropriately controlled.
In addition, in the case where different sorts of ECs to be mounted have different thickness values (i.e., different nominal thickness values), the movement of the nozzle and at least one of the EC-supplying device and the circuit substrate toward each other can be controlled based on the thickness of each EC determined based on the taken image, without needing to store, in a memory, data representing the respective thickness values of the different sorts of ECs. For example, in the case where a tendency of respective errors of thickness values of ECs supplied from the EC-supplying device can be determined and accordingly a thickness of an EC to be sucked next can be estimated based on the thickness values of the ECs that have been mounted, the movement of the nozzle and the EC-supplying device toward each other can be appropriately controlled to suck each EC, based on the respective thickness values of the ECs determined based on the respective taken images.
The EC mounting method according to the tenth feature (10) may employ any one of the above-described second to ninth features (2) to (9).
(11) According to an eleventh feature of the present invention, there is provided a method of mounting an electric component on a circuit substrate, the method comprising the steps of moving at least one of a suction nozzle and an electric-component supplying device toward the other of the suction nozzle and the electric-component supplying device, so that the nozzle applies a suction to the electric component supplied by the supplying device and thereby receives the component, moving at least one of the suction nozzle and the circuit substrate toward the other of the nozzle and the substrate, so that the nozzle mounts the electric component on the substrate, taking an image of at least an end portion of the nozzle that applies the suction, as seen in a direction perpendicular to an axial direction of the nozzle, in a state in which the nozzle takes a known position in the axial direction, determining, based on image data representing the taken image, a position, in the axial direction, of at least an end surface of the suction nozzle that applies the suction, and controlling, based on the determined position, a movement of at least one of the suction nozzle and at least one of the electric-component supplying device and the circuit substrate, toward the other of the nozzle and said at least one of the supplying device and the substrate.
An image to be taken may be an image of a lower end portion of the suction nozzle, or an image of the entirety of the nozzle.
Only an image of the suction nozzle may be taken, and only a position of the sucking end surface of the nozzle in the axial direction may be determined. In a state in which an EC is held by the nozzle, an image of the EC in addition to the nozzle may be taken, and a position of the mounted surface of the EC in the axial direction may additionally be determined. If an image of the nozzle is taken in the state in which the nozzle is not holding an EC, a position of the sucking end surface of the nozzle can be determined more accurately.
An image of the suction nozzle may be taken during an EC-taking action, or in a state in which the nozzle is not performing an EC-taking action. In the former case, it is possible to change, during the EC-taking action, the limit of movement of the nozzle toward an EC supplied from the EC-supplying device. In the latter case, an image of the nozzle is taken before an EC-taking action is started and, after the limit of movement of the nozzle is changed, the EC-taking action is started.
The eleventh feature (11) solves the problem that the movement of the suction nozzle and at least one of the EC-supplying device and the circuit substrate toward each other may not be well controlled because of the change of the position of the sucking end surface of the nozzle caused by the respective manufacturing errors of the nozzle and the nozzle holder and the wearing of the nozzle. Since the axial-direction position of the sucking end surface of the nozzle is determined based on the image data obtained in the state in which the nozzle takes the known axial-direction position, an error of the actual axial-direction position of the sucking end surface from a correct position can be obtained by comparison of the actual position with the correct position and, based on the thus obtained error, the movement of the nozzle and the EC-supplying device toward each other can be so controlled as to avoid a shortage or excessiveness of amount of the movement, a failure to suck an EC, or an occurrence of damaging of an EC. In the case where the thickness of an EC is small, the movement of the nozzle and the circuit substrate toward each other can be controlled, based on the obtained error, to avoid a failure to mount the EC or an occurrence of damaging of the EC. As described in connection with the first feature (1), the position of the sucking end surface of the nozzle may be determined as an absolute position thereof relative to a reference position.
The EC mounting method according to the eleventh feature (11) may employ any one of the above-described second to ninth features (2) to (9).
(12) According to a twelfth feature of the present invention that includes any one of the first to eleventh features (1) to (11), the taking step comprises taking, with a surface-image taking device which can take a two-dimensional image at once, a two-dimensional image of at least one of an end portion of the suction nozzle that applies the suction and the electric component sucked and held by the nozzle, as seen in the direction perpendicular to the axial direction of the nozzle.
(13) According to a thirteenth feature of the present invention that includes any one of the first to eleventh features (1) to (11), the taking step comprises taking, with a linear-image taking device, at least one linear image of at least one of an end portion of the suction nozzle that applies the suction and the electric component sucked and held by the nozzle, and wherein the determining step comprises determining, based on image data representing the taken linear image, a position of at least one of the mounted surface of the component and an end surface of the nozzle that applies the suction.
A two-dimensional image can be obtained by iteratively taking linear images while the linear-image taking device and the nozzle holder are moved relative to each other in a direction having a component perpendicular to the axial direction of the suction nozzle. This two-dimensional image may be one which includes the entirety of the end portion of the nozzle or the entirety of the EC, or one which includes only a portion of the end portion or the EC. In an extreme case, the two-dimensional image may be replaced with a single linear image. Based on the single linear image, it is possible to determine a position of at least one of the mounted surface of the EC and the sucking end surface of the nozzle.
(14) According to a fourteenth feature of the present invention, there is provided a method of treating an electric component, the method comprising the steps of causing a suction nozzle to apply a suction to the electric component supplied by an electric-component supplying device and thereby receive the component, taking an image of at least an end portion of the suction nozzle that applies the suction, as seen in a direction perpendicular to an axial direction of the nozzle, in a state in which the nozzle takes a known position in the axial direction, determining, based on image data representing the taken image, a position, in the axial direction, of at least an end surface of the suction nozzle that applies the suction, and controlling, based on the determined position, a movement of at least one of the suction nozzle and the electric-component supplying device, toward the other of the nozzle and the supplying device.
An image of the end portion of the suction nozzle may be taken in a state in which the nozzle is holding an EC or is not holding an EC, or in a state in which the nozzle is performing an EC-taking action or is not performing an EC-taking action.
The fourteenth feature (14) solves the problem that the movement of the suction nozzle and the EC-supplying device toward each other may not be well controlled because of the change of the position of the sucking end surface of the nozzle caused by the respective manufacturing errors of the nozzle and the nozzle holder and the wearing of the nozzle.
The EC mounting method according to the fourteenth feature (14) may employ any one of the above-described second, third, and fifth to thirteenth features (2), (3), and (5) to (13).
(15) According to a fifteenth feature of the present invention, there is provided an apparatus for mounting an electric component on a circuit substrate, the apparatus comprising an electric-component supplying device which supplies the electric component; a circuit-substrate supporting device which supports the circuit substrate; a nozzle holder which holds a suction nozzle having an end surface which applies a suction to the electric component supplied by the electric-component supplying device and thereby holds the component; a reception controller which controls at least one of the nozzle holder and the electric-component supplying device to be moved toward the other of the nozzle holder and the supplying device, so that the suction nozzle receives the electric component from the supplying device; a mounting controller which controls at least one of the nozzle holder and the circuit-substrate supporting device to be moved toward the other of the nozzle holder and the supporting device, so that the suction nozzle mounts the electric component on the circuit substrate supported by the supporting device; an image taking device which takes, during a time duration after the suction nozzle receives the electric component and before the nozzle mounts the component, an image of at least the component sucked and held by the nozzle, as seen in a direction perpendicular to an axial direction of the nozzle, in a state in which the nozzle holder takes a known position in the axial direction; an image processor which determines, based on image data representing the image taken by the image taking device, a position, in the axial direction, of at least a mounted surface of the electric component that is opposite to a sucked surface of the component sucked by the suction nozzle; and a control modifying device which modifies, based on the position determined by the image processor, at least one of the control of the reception controller to move said at least one of the nozzle holder and the electric-component supplying device, and the control of the mounting controller to move said at least one of the nozzle holder and the circuit-substrate supporting device.
The nozzle holder may be one which holds a plurality of suction nozzles, or one which holds a single suction nozzle.
The above description provided for, e.g., the EC mounting method according to the first feature (1) is true with the EC mounting apparatus according to the fifteenth feature (16).
The EC mounting apparatus according to the fifteenth feature (15) may employ any one of the above-described second to ninth, twelfth, and thirteenth features (2) to (9), (12), and (13).
(16) According to a sixteenth feature of the present invention, there is provided an apparatus for mounting an electric component on a circuit substrate, the apparatus comprising an electric-component supplying device which supplies the electric component; a circuit-substrate supporting device which supports the circuit substrate; a nozzle holder which holds a suction nozzle having an end surface which applies a suction to the electric component supplied by the electric-component supplying device and thereby holds the component; a reception controller which controls at least one of the nozzle holder and the electric-component supplying device to be moved toward the other of the nozzle holder and the supplying device, so that the suction nozzle receives the electric component from the supplying device; a mounting controller which controls at least one of the nozzle holder and the circuit-substrate supporting device to be moved toward the other of the nozzle holder and the supporting device, so that the suction nozzle mounts the electric component on the circuit substrate supported by the supporting device; an image taking device which takes, during a time duration after the suction nozzle receives the electric component and before the nozzle mounts the component, an image of the component sucked and held by the nozzle, as seen in a direction perpendicular to an axial direction of the nozzle; an image processor which determines, based on image data representing the image taken by the image taking device, a thickness of the electric component held by the suction nozzle; and a control modifying device which modifies, based on the thickness determined by the image processor, at least one of the control of the reception controller to move said at least one of the nozzle holder and the electric-component supplying device, and the control of the mounting controller to move said at least one of the nozzle holder and the circuit-substrate supporting device.
The above description provided for, e.g., the EC mounting method according to the tenth feature (10) is true with the EC mounting apparatus according to the sixteenth feature (16).
The EC mounting apparatus according to the sixteenth feature (16) may employ any one of the above-described second, third, fifth to ninth, twelfth, and thirteenth features (2), (3), (5) to (9), (12), and (13).
(17) According to a seventeenth feature of the present invention, there is provided an apparatus for mounting an electric component on a circuit substrate, the apparatus comprising an electric-component supplying device which supplies the electric component; a circuit-substrate supporting device which supports the circuit substrate; a nozzle holder which holds a suction nozzle having an end surface which applies a suction to the electric component supplied by the electric-component supplying device and thereby holds the component; a reception controller which controls at least one of the nozzle holder and the electric-component supplying device to be moved toward the other of the nozzle holder and the supplying device, so that the suction nozzle receives the electric component from the supplying device; a mounting controller which controls at least one of the nozzle holder and the circuit-substrate supporting device to be moved toward the other of the nozzle holder and the supporting device, so that the suction nozzle mounts the electric component on the circuit substrate supported by the supporting device; an image taking device which takes an image of at least an end portion of the suction nozzle that applies the suction, as seen in a direction perpendicular to an axial direction of the nozzle, in a state in which the nozzle holder takes a known position in the axial direction; an image processor which determines, based on image data representing the image taken by the image taking device, a position, in the axial direction, of at least an end surface of the suction nozzle that applies the suction; and a control modifying device which modifies, based on the position determined by the image processor, at least one of the control of the reception controller to move said at least one of the nozzle holder and the electric-component supplying device, and the control of the mounting controller to move said at least one of the nozzle holder and the circuit-substrate supporting device.
The above description provided for, e.g., the EC mounting method according to the eleventh feature (11) is true with the EC mounting apparatus according to the seventeenth feature (17).
The EC mounting apparatus according to the seventeenth feature (17) may employ any one of the above-described second, third, fifth to ninth, twelfth, and thirteenth features (2), (3), (5) to (9), (12), and (13).
(18) According to an eighteenth feature of the present invention that includes any one of the fifteenth to seventeenth features (15) to (17), the circuit-substrate supporting device comprises a support member which supports the circuit substrate, and wherein the mounting controller comprises a holder elevating and lowering device which elevates and lowers the nozzle holder in the axial direction of the suction nozzle in a prescribed range, and smoothly decelerates a downward movement of the holder in a terminal portion of the range; and a substrate elevating and lowering device which elevates and lowers, based on the position determined by the image processor, the support member supporting the circuit substrate.
According to the eighteenth feature (18), even if there may be a change of the position of the sucking end surface of the suction nozzle caused by the manufacturing error and/or wearing of the nozzle, the support member may be elevated or lowered to adjust the position of the support surface of the circuit substrate that supports one or more ECs mounted thereon, so that the EC held by the nozzle may contact the substrate after the speed of downward movement of the nozzle holder has been reduced to a low value. Thus, the EC is mounted on the substrate without being damaged.
(19) According to a nineteenth feature of the present invention that includes any one of the fifteenth to eighteenth features (15) to (18), the apparatus further comprising a transferring controller which controls the nozzle holder to be moved between the electric-component supplying device and the circuit-substrate supporting device, so that the suction nozzle transfers the electric component from the electric-component supplying device to the circuit-substrate supporting device.
The transferring controller may be one which is recited in the following, twentieth feature (20), or one which causes a linear movement of the suction nozzle to transfer the EC. The linear movement may be done in a direction contained in a plane parallel to the support surface of the circuit substrate that supports one or more ECs mounted thereon, or in a direction having two components respectively parallel to two directions perpendicular to each other in the plane.
(20) According to a twentieth feature of the present invention that includes the nineteenth feature (19), the transferring controller comprises a revolving device which revolves a plurality of the nozzle holders about an axis line and stops each of the nozzle holders at each of an electric-component-receive position and an electric-component-mount position which are provided on a locus of revolution of the each nozzle holder.
The axis line of revolution may be substantially vertical, or may be inclined relative to a vertical plane.
(21) According to a twenty-first feature of the present invention that includes the twentieth feature (20), the image taking device is provided inside the locus of revolution of the each nozzle holder, such that the image taking device faces toward outside the locus of revolution.
Alternatively, the image taking device may be provided outside the locus of revolution of each nozzle holder. However, in the case where the image taking device is provided inside the locus, an otherwise vacant space left below the revolving device as seen in a direction parallel to the axis line of revolution can be effectively utilized.
(22) According to a twenty-second feature of the present invention that includes the twenty-first feature (21), the apparatus further comprising a lighting device which is provided outside the locus of revolution of the each nozzle holder and faces toward the image taking device.
(23) According to a twenty-third feature of the present invention, there is provided an apparatus for treating an electric component, the apparatus comprising an electric-component supplying device which supplies the electric component; a nozzle holder which holds a suction nozzle having an end surface which applies a suction to the electric component supplied by the electric-component supplying device and thereby holds the component; a reception controller which controls at least one of the nozzle holder and the electric-component supplying device to be moved toward the other of the nozzle holder and the supplying device, so that the suction nozzle receives the electric component from the supplying device; an image taking device which takes an image of at least an end portion of the suction nozzle that applies the suction, as seen in a direction perpendicular to an axial direction of the nozzle, in a state in which the nozzle holder takes a known position in the axial direction and the suction nozzle does not hold an electric component; an image processor which determines, based on image data representing the image taken by the image taking device, a position, in the axial direction, of at least an end surface of the suction nozzle that applies the suction; and a control modifying device which modifies, based on the position determined by the image processor, the control of the reception controller to move said at least one of the nozzle holder and the electric-component supplying device.
If an image is taken during an EC treating action, the control is modified during the EC treating action. On the other hand, if an image is taken in a state in which an EC treating action is not performed, the control is modified before the next EC treating action is started.
The EC treating apparatus according to the twenty-third feature (23) may employ any one of the above-described second, third, fifth to ninth, twelfth, and thirteenth features (2), (3), (5) to (9), (12), and (13).